This warmer has a compact footprint, is light at 1.5 pounds, and fits both narrow and wide mouth bottles. Here in use with Editors' Choice Lifefactory baby bottle.
The Kiinde company was founded by two MIT engineers (and dads) who envisioned an opportunity to improve infant feeding via a unique bottle warmer. From here, their line has since expanded to a complete system which includes the Kiinde Squeeze
baby bottle whose Kiinde Twist Pouch
hooks up to any breast pump via a variety of adapters for direct pump-to-pouch expression. A uniquely designed Kiinde Keeper
then accentuates the system with a modern freezer storage solution that is designed to avoid bag puncture.
Kiinde's water bath technology is termed SAFEHeat and that's exactly what it does, that is, safely heats breast milk or formula (frozen or refrigerated) at a low temperature, nutrient-preserving water bath. The company states that this is the first warmer designed specifically to follow all guidelines set forth by the Center for Disease Control and the United States Department of Agriculture to safely thaw and warm breast milk.
Health and Safety
We like Kiinde's SAFEheat technology, especially when it comes to warming breast milk.
The Kiinde Kozii received an 8 of 10 in the health and safety metric. It has a warming time chart with recommended settings for a starting point. Following this approach will circumvent opportunity for overheating. Though instructions are clear, we would like to see Kiinde attach a warming chart to the back of the device similar to that provided by the Born Free Tru-Temp
and the Cuisinart BW-10
for easily accessible, quick viewing.
An innovative feature of the Kozii is at turn on, an internal convection pump sends water up and out of the reservoir to flow around the container. There is an overflow valve at the top where water flows back into the reservoir should the unit be filled higher than the "Full" indicator. At auto shut-off, water drains back into its reservoir. This means that, heat is mostly removed from the bottle as soon as it shuts off and users are less likely to come into contact with warm water. However, like other warmers, if set to too high a heating setting, the Kozi can be made to overheat milk.
During use, the water level rises up into the warming chamber of the Kiinde and creates a gentle, circulating warm water bath. After shut off, the water drains back into the hidden water reservoir.
As the Kozii doesn't have a end of cycle beep, we recommend setting a separate timer to alert when a bottle is ready. The timer does run a low "ticking" noise for 30 seconds at the end of cycle, but it isn't loud enough. Even though water retracts back into the reservoir, if a bottle sits inside the chamber, milk temperature will continue to rise until removal.
In our testing, the Kiinde had the very best performance of any tested warmer when used at the manufacturer's recommended settings. It shut off as it reached 80F and then continued to warm gradually to reach no higher than body temperature. However, in our maximum heating test, where we ignored the manufacturer's recommendations and simply turned it to maximum and left it running, we did find that the Kiinde would overheat and after 12 minutes reached 122F. It is worth noting that 3 of the 7 competing warmers never overheated in our tests, even when run at their maximum heating setting. Thus, we'd advise following Kiinde's instructions for the Kozii, since even this sophisticated device can overheat if misused.
Ease of Use
Kozii's Simple Start Guide makes it easy to get started right out of the box. A minute-based control dial makes timing clear.
The Kozii earned a 9 of 10 in ease of use. It is compact with a one-piece design right out of the box, so there is virtually zero set-up. A Simple Start Guide makes it easy to get warming right away. However, we do recommend reading Instruction Manual and Troubleshooting Tips as it offers simple advice on best usage practices to keep it in good working order.
Its water chamber fits standard and wide-mouth bottles such as the Top Pick Comotomo and Best Value Tommee Tippee Feeding as well as any material including plastic, glass, silicone, and stainless that may be found in such items as breast milk storage bags, liner bottles, and baby food jars.
The reservoir is easy to fill with a 2 cup capacity. Refilling only need occur about every 5 to 10 uses. The minute timer is intuitive and lets you know how much time is left before baby's meal is ready. For use, fill the warming chamber with water to just above the word "Full"; there should always be water between "Empty" and "Full." That's all it takes before you're ready to warm.
During the warming cycle, the chamber fills with warm, circulating water via an internal convection pump, gently heating the bottle. At baseline, the Kozii emits a consistent hum and tick-ticking. At the end of the cycle, just before it automatically shuts off, water retracts back down into the reservoir. If you need to heat another bottle, you can start the unit up right away, just be sure to reduce the time by 30 seconds.
We do wish this warmer had an audible end of cycle beep to let you know when the time is up. We feel the ticking just isn't loud enough and when it turns off about 30 seconds after the cycle is complete, it can be easily tuned out and missed.
The Kozii earned an 8 of 10 in warming efficiency. Depending on the bottle material, quantity and starting temperature of milk, it could take anywhere between 4 to over 12 minutes to warm milk via its gentle circulating warm water bath. It will take a short initial trial period to find the right setting for your particular needs. So, be patient. The extra time is well worth it to preserve breast milk nutrients.
Warming a storage bag filled with expressed breast milk in Editors' Choice Kiinde Kozii.
Keep in mind, frozen will take longer! Frozen storage bags of breast milk may take upwards of 12 minutes. For this situation, Kiinde recommends warming a frozen bag for 5 minutes, then pushing the frozen milk to bottom of bag and continue warming.
However, once that sweet spot is found, the Kozii executes warming consistently. In our testing, at recommended settings, it took 4 ounces of refrigerated milk in a small Lifefactory Glass Bottle with silicone sleeve 5:50 to reach 80F and at maximum setting, 6:00 to reach the same temperature.
For best consistency, efficiency, and quiet with the Kozii, make sure that water is constantly flowing through the overflow drain during warming. If you have a small bottle or a bag of breastmilk (typically lighter than a bottle), then you may need to add water above the "Fill" indicator; there is a secondary line inside the chamber for this use.
Always make sure the Kozii has sufficient water prior to running. In the event that the Kozii is run dry, its safety thermostat may trip which will mean that its water bath will not be heated. In this event, you need to re-set the system following the troubleshooting instructions. However, do not make this a habit as the entire system will stop working permanently if it is tripped more than 3 times.
Ease of Cleaning
The Kozii scored a 4 of 10 in ease of cleaning which is a straightforward but involved process. With a hidden reservoir, it is important to follow cleaning instructions to avoid mold growth as well as hard mineral build-up internally.
- Every 2 to 3 Days — Rinse inside reservoir with mild soap:water solution and wipe chamber and outside with wet, soapy sponge. Air dry.
- Every 2 Weeks — Perform above using 1:50 bleach solution instead of soap. Fill Kozii completely including overflow drain and let sit 10 minutes. Rinse 3 times and run unit with 2 cups fresh water for 3 minutes.
- Every 2 Months — Descale with 1/2 cup white vinegar: 1 cup cold water and pour into chamber. Let stand 10 to 20 minutes with unit unplugged. Pour vinegar solution out via overflow drain. Rinse with fresh water 3 times, swirling gently.
Great for home use, daycare, or travel, the Kozii is versatile with even the widest of bottle systems. It is compact and easy to use, but make sure you have patience for regular maintenance. With a circulating water bath, it is perfect for those who are warming expressed breastmilk. And, without a wait time between uses, it is a also great warmer to use with multiples.
The most important capability of a bottle warmer is to warm breast milk without overheating it to the point that nutrients are lost. But, there are other practical considerations such as will your favorite bottle fit inside? Wide bottles easily fit into the Kiinde.
In our opinion, Kozii's innovative technology is worth its price tag of $70. If you're looking for a more budget-friendly option, however, the slower but very functional Chicco NaturalFit Two-in-One is the way to go.
Kiinde's design of Editors' Choice Kozii is unique with SAFEheat technology and a hidden water reservoir with internal convection pump. Excelling in health and safety, ease of use, and warming efficiency, a bit of extra time spent warming is well-worth the wait. We highly recommend this warmer. It certainly stands out in the crowd of available warmers.